UPD77114 Просмотр технического описания (PDF) - NEC => Renesas Technology

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производитель

UPD77114

16-BIT FIXED-POINT DIGITAL SIGNAL PROCESSORS

NEC => Renesas Technology 

µPD77113A, 77114

3. CLOCK GENERATOR

The clock generator generates an internal system clock based on the external clock input from the CLKIN pin and

supplies the generated clock to the internal units of the DSP.

For details of how to set the PLL multiple, refer to 4.2 Initializing PLL, and 8.1 Clock Control Options.

Stop mode

Halt mode

CLKIN

CLKOUT

PLL control circuit

×m

Output divider

÷n

Halt divider

÷l

Internal

system clock

4. RESET FUNCTION

When a low level of a specified width is input to the RESET pin, the device is initialized.

4.1 Hardware Reset

If the RESET pin is asserted active (low level) for a specified period, the internal circuitry of the DSP is initialized.

If the RESET pin is then deasserted inactive (high level), boot processing of the instruction RAM is performed

according to the status of the port pins (P0 and P1). After boot processing, processing is executed starting from the

instruction at address 0x200 of instruction memory (reset entry). In addition, a self-check is performed by the internal

data RAM at the same time as the boot processing. This check takes about 20 ms (at 50 MHz operation, the length

of this period is in inverse proportion to the operating frequency.)

On power application, the RESET pin must be asserted active (low level) after 4 input clocks have been input with

the RESET pin in the inactive status (high level), after the supply voltage has reached the level of the operating

voltage. In other words, no power-ON reset function is available. On power application, the PLL must be initialized.

20

Data Sheet U14373EJ3V0DS

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